ARLINGTON, Va. - Drivers can expect major delays on Sunday as approximately 27,000 runners take off for the 42nd annual Marine Corps Marathon.

There will also be an MCM10K and Kids Run.

Officials expect 100,000 supporters and spectators scattered throughout the route as well.

The race, organized by the men and women of the United States Marine Corps, is the largest marathon in the world that doesn't offer prize money, instead celebrating the honor, courage and commitment of all finishers.

"It takes dedication to be a Marine, it also takes dedication to train for a marathon," says Colonel Joe Murray, Commanding Officer of the MCM.

On Friday, thousands stopped by the Gaylord National Resort and Convention Center at the National Mall to pick up their packets and enjoy the more than 200 exhibits.

The participants include service members from all different military branches, first-time marathon runners, and those who have run several.

On the day of the race, MCM officials say 2,300 Marine volunteers team up with more than 850 officers from a number of local police agencies to keep a close watch, among other security procedures.

"Before you go into the actual race area there’s going to be a number of screening points," says Major A.J. Bormann. "There are active barricades throughout the course, all around, strategically placed to prevent any type of vehicle that would want to cause harm to someone throughout the race."

To view the long list of closures throughout Virginia and in D.C. on Sunday, visit the MCM website.

MCM will also provide free shuttles from various metro stops to the race. For more information on the shuttles and best options for transportation, click here.